Communication among low-cost devices is useful in many applications. For example, in a home environment, room occupancy sensors, light switches, lamp dimmers, and a gate-way to the Internet can all work together if they are in communication. A room in a home could be illuminated when people are present, or else an alarm could be sounded, depending on conditions established by a program running on a remote computer.
Home automation systems can use existing powerline wiring as a communication network to communicate messages between devices that receive power from the powerline. However, many devices operate remotely from the household powerline wiring, such as battery operated devices and low voltage devices, and are prevented from communicating over the powerline network.